In some industrial fields using fluid networks, it is necessary to check the tightness of these networks.
E.g., in the context of an aircraft, there are many fluid networks allowing the flow of liquids or gases.
E.g., in the case of fuel tanks, there is a pipe that connects the tanks with each other and each end of which passes through the wall of a tank and opens into the inside of the tank. This pipe allows the transfer of the fuel from one tank to the other. A check valve is arranged at each end of the pipe opening into a tank.
The check valve is suspended inside a downwardly open housing and the housing is attached onto the wall of the tank opposite the end of the pipe.
When the tightness of the supply circuit has to be tested, each housing is removed and a plug is pushed into the corresponding end of the pipe. The circuit is then placed under pressure for checking that there is no leak.
Although such a checking method gives good results, it is relatively lengthy to implement since it is necessary to dismantle the housings and then refit them at the end of checking.